Printer having type disk rotatable in a plane parallel to the printing line



Dec. 5, 1967 A L. P. ROBINSON 3,356,199

PRINTER HAVING TYPE DISK ROTATABLE IN A PLANE PARALLEL TO THE PRINTINGLINE Filed Feb. 23, 1966 VACUUM SOURCE V PRINT LIN LELAND F? ROBINSONINVENTOR.

ATTORNEY United States Patent M 3,356,199 PRINTER HAVING TYPE DISKROTATABLE IN A PLANE PARALLEL TO THE PRINTING LINE Leland P. Robinson,Oakland, Calif., assignor to Friden, Inc., a corporation of DelawareFiled Feb. 23, 1966, Ser. No. 529,455 9 Claims. (Cl. 197--54) ABSTRACTOF THE DISCLOSURE A high-speed printer utilizing a continuously rotatingtype wheel having at least one group of type characters on its face.Preferably, a plurality of similar groups of type characters areprovided. Each group is arranged spirally relative to the center of thewheel and each type character is preferably supported on the face of acorresponding spoke or radial extension. During the continuous rotationof the type wheel, the wheel is moved continuously in a plane parallelto the path of line printing. With each predetermined angular rotationof the wheel, a desired character of a group may be printed in acolumnar print position of the printing line due to the spiralarrangement of the type characters.

This invention relates to high-speed printers capable of printinginformation received from data handling apparatus, such as computers orcalculators by way of example.

With the advent of computer technology and advances in the art of dataprocessing, requirements for increased speed of handling informationhave become more stringent. One known type of rapid readout withpermanent recordation incorporates a high-speed printer that employs acharacter type Wheel bearing the characters to be printed at the outerperiphery of respective spokes forming the wheel. In such prior artapparatus, the character wheel is advanced intermittently from one printposition to the next, while it rotates continuously. However, such stopand start operation tends to reduce the speed of the system, and alsocauses undue wear and tear on the mechanical parts.

An object of the present invention is to provide a novel and improvedon-the-fiy high-speed printer, wherein the character supporting assemblyis rotated continuously while being transported continually along thepath of line printing, without interruption during each cycle of lineprinting.

According to this invention, a high-speed printer comprises a rotarymeans having type faces representing characters to be printed, the typefaces being disposed in at least one group defining a spiral path. Therotary type means, which may be a wheel with separate spokes supportingtype symbols or characters, is continuously rotated and is urged alongthe path or line of print conjointly with a striking hammer toeffectuate printing on a record medium or paper. The type wheeltraverses the print line in a continuous and noninterrupted motion,precluding those problems that arise from intermittent operation such asfound in prior art devices.

The spiral arrangement of the characters or symbols compensates forlateral displacement of the rotating type faces resulting from thecontinuous linear motion of the type wheel along the path of the line ofprinting. As a result of such compensation, each character of the groupappears at substantially the same spot for each particular printposition.

In a particular embodiment, each half or semicircular portion of thetype wheel carries a separate group of spirally disposed characters fromwhich one character 3,356,199 Patented Dec. 5, 1967 may be selected forprinting while the wheel is on-thefly. The groups are identical and likecharacters are substantially diametrically opposed.

The invention will be described in greater detail with reference to thedrawing in which:

FIG. 1 is a front elevational view, partly broken away, of the printerapparatus of this invention;

FIG. 2 is a side elevational view of the novel printer, taken along aplane indicated by the line 22 of FIG. 1; and

FIG. 3 depicts the novel character wheel in two different printingpositions along the same print line.

Similar numerals refer to similar elements throughout the drawing.

With reference to the figures of the drawing, an embodiment of ahigh-speed printer, in accordance with this invention, comprises a typeWheel 10 formed with resilient, flexible spokes 12, each spokesupporting a character or symbol near the periphery of the wheel. Inthis particular embodiment, two identical groups of characters aredisposed in diametric relation, each group occupying a semicircularportion of the wheel 10. At the end of each group of characters there isone spoke 13 that is blank to provide a gap hiatus (see FIG. 3), wherebya suitable interval is provided for retraction and resetting of a printhammer 22 used in the printing operation.

To achieve rotary motion, the type wheel 10 is driven by a pinion gear14 that is actuated by a rack 16 in a wellknown manner, the axis of thegear and type wheel being at a right angle to the printing line. Itshould be understood that the gear configuration and gear ratiosdepicted herein are merely illustrative, and should not be interpretedas exclusionary. The characters, shown as numerals in the wheel 10,rotate clockwise in the illustrated embodiment, and are disposed so asto form a spiral configuration for each character group, each groupspiral,

characterized by a decreasing radius of curvature in the direction ofrotation of the wheel.

The wheel 10 is coupled to a carriage 18 that is transported linearlyalong a rotatable drive screw or threaded shaft 20, which is fixed withits axis substantially parallel to the proposed paths of line printing.Also mounted to the carriage 18 is the print hammer assembly 22 utilizedfor striking a selected character at each print position, wherebyprinting on a record medium or paper 24 is effectuated. The paper 24 islocated between a fixed platen 26 and an ink ribbon 28 which is fed froma supply spool 29. Self-inked papers or the like may be used toeliminate the need for the ribbon.

The platen 26, which is secured to a rigid frame 27, has two axial rowsof apertures 31 that provide suction for firm adherence of the paper 24to the platen. Pressure supply or a vacuum source 33 maintains thenecessary suction during the print cycle. During the interval betweeneach line of printing, the suction is removed by valve means, forexample, to allow facile advance of the paper to the next line position.

A return spring 30 is provided to urge the carriage 18 back to Home orstart position at the end of each cycle of line printing. A detent pin32 is provided for coupling the carriage 18 to the drive screw 20 duringprint operation, and for decoupling the carriage to allow springretraction between print cycles, as disclosed in .copending applicationSer. No. 528,501, filed Feb. 18, 1966, in behalf of Leland Chamness etal., and assigned to the same assignee. The source of power drive forthe carriage and type wheel, as well as other conventional partscommonly used in printer apparatus, are not shown for the purposes ofconvenience and clarity.

In operation, the carriage 18 is moved with the rotating wheel 10 andprint hammer 22 in a longitudinal path defining the direction of serialprinting of the line characters. As depicted in FIG. 3, at a firstposition of a given print line, the Wheel 10a is in position forprinting the numeral. Any numeral in the semicircular group 0 to 9 willappear in substantially the same print position or spot, delineated bythe rectangle encompassing the 0. Similarly, at a second print positionfurther along the print line, the wheel is represented with the numeral4 in position for selection for imprinting. The print hammer 22 is madesufficiently wide, preferably two column widths, so as to be capable ofprinting at a selected column, regardless of where the selectedcharacter appears.

Each character of a group is positioned at successively shorterdistances from the center of curvature of the spiral defined by thecharacters. The difference in such distance between adjacent charactersis substantially equal to the amount of linear displacement of thecarriage and print Wheel along the print line, which occurs during theinterval that the wheel is rotated from one numeral to the next in thesame group. Also, when the last numeral 9 in a group has passed printposition, the succeeding O of the next group which is positioned apredetermined distance further from the center of curvature than thepreceding 9, traverses the next print position. It is evident that thedifference in length between the radius of curvature of the 9 characterand that of the 0 character of the succeeding group substantiallyrepresents the distance between adjacent print positions. The angularvelocity of the print wheel 10 is such that for every 180 of rotation ofthe wheel 10, the carriage is translated axially from one print positionto the next; and thus, for each complete revolution of the print Wheel,the carriage and print wheel traverses two print positions.

It should be noted that with two separate groups of numerals, selectionof a numeral for printing will be made alternately from each group. Thatis, each alternate print position is accommodated by one group ofnumerals, while the second group provides the other interspaced printpositions with a selected numeral to be printed. Thus, if N groups ofnumerals are used, each group would provide a character for every Nthprint position.

Selection of a character for printing may be accomplished by any one ofseveral known means, such as by an optical system employing a radiationsource and photosensing means cooperating with a timing disk having areference aperture and a series of holes, each hole corresponding to adifferent character position. Input data received from a keyboard,punched tape, or recorded magnetic tape, for example, serves to actuatethe print hammer when a selected character is in print position.

By employing a plurality of character groups, the hammer is allowedample time to strike a selected spoke of one character group at oneprint position. As described heretofore, a blank spoke or space isprovided at the end of each character group to allow recovery time forthe hammer. Thus, while the type wheel advances to the next charactergroup, the hammer is able to retract and recover to ready position, sothat it can be triggered to strike a character from the succeeding groupat the next print position.

It should be understood that various modifications and alternatives ofthe embodiment described above are possible within the scope of thisinvention. For example, a plurality of wheels of different diameters maybe employed with associated hammers for the simultaneous printing of aplurality of characters along a line, or in some other predeterminedconfiguration. Also, the arrangement of the paper and ribbon relative tothe type wheel and hammer may be changed, and the drive system may bemodified accordingly. 4

What is claimed is:

1. A high-speed printer apparatus comprising:

a rotary wheel supporting a plurality of type characters on one sidesurface, said characters being disposed in a spiral curve recedingtoward the axis of said wheel;

means for rotating said wheel continuously during each cycle of lineprinting and in a plane parallel to the printing line;

a print hammer for striking selected characters to print a line duringeach of such print cycles; and

means for transporting said wheel and said hammer relative to a recordmedium, continuously and without interrupted travel along apredetermined line of. printing.

2. A high-speed printer apparatus as in claim 1 wherein said typecharacters are disposed in a plurality of separate groups on said wheel,each group of characters defining a separate spiral path toward the axisof said wheel.

3. A high-speed printer apparatus as in claim 2 wherein said separategroups are substantially identical.

4. A high-speed printer apparatus as in claim 2 wherein such pluralitycomprises two groups, each group positioned within a semicircularportion of a side surface of said Wheel.

5. A high-speed printer apparatus as in claim 4 wherein the two groupsconsist of like characters, similar characters of each group beingsubstantially dimetrically opposed.

6. A high-speed printer apparatus as in claim 1 including power meansfor returning said hammer and wheel to home position at the end of eachcycle of line printing, and means for disabling said transporting meansand enabling said power means.

7. A high-speed printer apparatus as in claim 2 wherein said wheelcomprises a multiplicity of separate spokes, each said spoke supportinga type character and the characters being disposed spirally on therespective spokes receding from the periphery of the wheel.

8. A high-speed printer apparatus as in claim 7 wherein said spokes aregrouped in different portions of the wheel, and the characters of eachgroup define a spiral having a decreasing radius of curvature.

9. A high-speed printer apparatus as in claim 8 wherein the differencein length of the radius of curvature of the last character of a group,and that of the first character of the succeeding group is substantiallyequivalent to the distance between adjacent print positions in aprinting line.

References Cited UNITED STATES PATENTS 438,430 10/1890 Clerk 197531,189,449 7/1916 Highley 19754 2,060,082 11/1936 Johnson et al. 10l382 X2,236,663 4/1941 Adams 19753 2,484,671 10/1949 Bauman 101 2,590,0443/1952 Schaller 101382 X 2,831,424 4/1958 MacDonald 1971 X 2,843,2437/1958 Masterson 101-93 X 2,926,602 3/1960 MacDonald et al 101933,023,731 3/ 1962 Schwertz. 3,128,693 4/1964 Thiemann 10193 3,151,54710/1964 Hornmaner et al. 19749 X 3,220,343 11/1965 Wasserman l0l-933,247,788 4/1966 Wilkins et al. 101-93 ROBERT E. PULFREY, PrimaryExaminer.

E. S, BURR, Examiner.

1. A HIGH-SPEED PRINGER APPARATUS COMPRISING: A ROTARY WHEEL SUPPORTING A PLURALITY OF TYPE CHARACTERS ON ONE SIDE SURFADE, SAID CHARACTERS BEING DISPOSED IN A SPIRAL CURVE RECEDING TOWARD THE AXIS OF SAID WHEEL; MEANS FOR ROTATING SAID WHEEL CONTINUOUSLY DURING EACH CYCLE OF LINE PRINTING AND IN A PLANE PARALLEL TO THE PRINTING LINE; A PRINT HAMMER FOR STRIKING SELECTED CHARACTERS TO PRINT A LINE DURING EACH OF SUCH PRINT CYCLES; AND MEANS FOR TRANSPORTING SAID WHEEL AND SAID HAMMER RELATIVE TO A RECORD MEDIUM, CONTINUOUSLY AND WITHOUT INTERRUPTED TRAVEL ALONG A PREDETERMINED LINE OF PRINTING. 